Field of Invention
The present invention relates to a system and a method. More particularly, the present invention relates to a power supply system and a method for supplying power.
Description of Related Art
With advancements in power converter technology, characteristics such as high power, high efficiency, high power density, enhanced reliability and low cost have gradually become the focus of future development in the area of power converter technology. Moreover, to increase the reliability in power supply use, many electronic devices require the use of an uninterrupted power supply (UPS) to supply electricity. However, the UPS system is expensive and the use thereof is often limited by location, causing inconvenience in its application.
To improve the problems existing in the UPS system and to provide reliability in power supply use, a dual-supply rectifying power supply has been developed. Since the dual-supply rectifying power supply is coupled to two separate isolated power sources at the same time, as long as one of the two power sources can provide electricity, the dual-supply rectifying power supply can supply power to electronic devices, and hence, the dual-supply rectifying power supply can be used as a substitute for the UPS system. Also, the dual-supply rectifying power supply has the characteristics of low cost, compact size and high efficiency, and hence, it is suitable for use as a reliable power supply.
However, as discussed hereinbelow, there are some inconveniences associated with currently available dual-supply rectifying power supplies. To effectively isolate the two inputting power sources, a general dual-supply rectifying power supply will use a switch with a specific specification, such as a relay, to ensure the electrical isolation of the two power sources. However, when using such a mechanical-type switch, since the actuation time thereof is long, it requires a greater capacitance to maintain, resulting in a bigger overall volume of the dual-supply rectifying power supply. Further, such a dual-supply rectifying power supply may only be used with an alternating input source. When it is to receive a direct current input source, a large high-voltage converting switch is required, and as a result, the overall volume of the dual-supply rectifying power supply is increased.
Moreover, in another type of dual-supply rectifying power supply, since an input terminal thereof uses an isolated DC/DC converter, it cannot be compatible with alternating current and direct current at the same time. However, in actual application, the input power source may be an alternating current or direct current, and hence, the application of such a dual-supply rectifying power supply is limited.
In view of the foregoing, there are problems and disadvantages associated with existing products that await further improvement. However, those skilled in the art have been unable to find a solution.